Sex differences in locomotor recovery across mating contexts in Drosophila melanogaster

Mating behaviour plays a key role in animal reproduction and profoundly affects the physiological state and behavioural performance of individuals. Although numerous studies have focused on the behavioural responses of single-sex groups of Drosophila melanogaster under mating contexts, systematic comparisons of male and female fruit flies across different mating contexts are still relatively limited. This study investigated the locomotion of 86 male and female fruit flies under different mating contexts, including virgin, continuously exposed to the opposite sex (mated), beginning cohabitation with the opposite sex on the 8th day of the experiment (virgin-mated), and opposite-sex cohabitation on the 8th day and switching to same-sex cohabitation (mated-deprived). The results showed that virgin males exhibited the highest overall movement speed and that continuous exposure to the opposite sex led to a transient reduction in male movement speed. In contrast, females displayed a temporary increase in movement speed under opposite-sex cohabitation but rapidly returned to levels comparable to virgins. These sex-specific and time-dependent changes indicate that mating context exerts dynamic effects on movement speed. Moreover, in contrast to the negative effects of social isolation reported in previous studies, our findings suggest that mating status and social environment jointly shape locomotor performance under non-isolated conditions. Overall, this study highlights how males and females dynamically adjust locomotor strategies in response to changing reproductive and social contexts, providing an evolutionary perspective on behavioural plasticity and sex-specific trade-offs in insects.